하지방사통을 동반한 성인 협부결손성 요추전방전위증의 후방요추간유합술 및 추경나사고정술후 추적결과

최철,김근수,최하영,김철진,김형일,이정청 대한신경외과학회 1999 Journal of Korean neurosurgical society Vol.28 No.4

산업보건관리자를 위한 소음성 난청 예방지침서의 개발

이원철,유경혜,장성실,이세훈,구정완,김현욱,노영만,이경재,김형아 가톨릭 대학 산업의학 쎈타 산업의학연구소 1996 韓國의 産業醫學 Vol.35 No.1

Occupational hearing loss became the leading occupational disease by constioution 56% of all work-related diseases in Korea. However, the prevalance rates showed wide variations among the specific medical examination providers and were very low(0.8-1.4%) compared with those 8.4% in Japan. The sources of these variations was regarded in the preview study as 1) Employee audometric estings were primarily conducted by nurses and nurse-aids who had no formal training for audiometry; 2) althought audiometric testing equipment used by the spedific medical examination providers, it should be periodically calibrated, a significant number of them were not properly calibrated : 3) Initial audiometric testings were conducted at any available spaces in workplace or at the testing room without considering bachground noise level. One of solutions that can be done for sloving surrent noise related problems is to provide a noise related manual for the occupational health managers including doctors, nurses and hyginests. This study was done to provide such a manual. The main core of the manual was hearing conservation program. And the contents of the manual was the same as the main frame of hearing conservation program such as noise survey, provided of the diagram showing the core contents of each factor of the hearing conservation program. Hopefully, this manual will be the references of the standardized performances of the specific medical examination providers.

3차원 근거리 표적의 효과적인 위치 추정 알고리듬

이철목,이수형,박상배 위덕대학교 산업기술연구소 2000 산업기술연구소 논문집 Vol.4 No.1

본 논문에서는 다중 3차원 근거리표적의 위치를 효과적으로 추정하는 기법을 제안하였다. 제안한 기법은 세 개의 부분센서배열을 이용하여 기존의 3D MUSIC에서의 3차원 탐색을 3번의 1차원 탐색으로 대치함으로써 연 산량을 감소시켰다. 각각의 부분센서배열에서 얻은 센서신호로부터 표적이 원거리에 있다고 가정하고 원거리 입체각을 추정하면 추정된 입체각은 실제 근거리 표적의 위치인 방위각, 고각, 거리의 함수로 주어진다. 그러므로 세 개의 부분센서배열로부터 얻은 세 개의 함수를 연립하여 풀면 실제 근거리표적의 위치를 추정할 수 있다. 또 한 다중 표적의 경우, 추정치에 대하여 3차원 MUSIC 스펙트럼값을 비교함으로써 연관 문제를 해결하였다. In this paper, we are proposing an efficient 3D source localization algorithm using 3 uniform linear subarrays. The proposed algorithm replaces 3D search required in conventional 3D MUSIC algorithm with 3 1D searches, and thus reduces computational burden. The estimate of the 1D conic angle obtained from a subarray under the far-field assumption satisfies a nonlinear algebraic equation of the true source bearing angle, elevation angle, and range. The proposed algorithm estimates source location by solving 3 algebraic equations obtained from 3 subarrays. Comparing 3D MUSIC spectrums of the estimated source locations, the proposed algorithm solves pairing problem for multiple sources localization.

소뇌와 뇌간의 경색환자에서 자기공명 혈관 촬영술의 임상적 유용성

김형철,송홍기,이병철 대한신경과학회 1996 대한신경과학회지 Vol.14 No.1

인천지역 TDI 노출 작업자에서 직업성천식 유병율

김형렬,김철우,홍윤철,전형준,김치년,김현수,이지나,신주연,고동희,노재훈 大韓産業醫學會 2004 대한직업환경의학회지 Vol.16 No.2

목적 : TDI는 직업성천식을 일으키는 대표적인 물질로 알려져 있다. 과거 TDI에 노출된 작업자들의 천식 발생률을 5~6%가량 보고하였고, 국내에서도 2-20%에 이르는 유병율을 보고한바 있다. 작업환경이 많이 개선되고, 노출량이 감소된 최근에도 TDI에 의한 직업성천식에 대한 보고가 많이 이루어지고 있어, 이에 대한 적극적인 조사와 진단과정을 통해 유병율을 구하고 질병발생의 변화양상을 파악해 보고자 하였다. 방법 : 인천지역에서 특수건강진단을 수행하는 2개 기관의 TDI 노출 근로자 400여명 중, 사업장의 규모가 50인 이상이며 사업주가 연구진행을 허락한 사업장에서 근무하는 근로자 중 직접적으로 TDI에 노출되는 작업에 종사하는 근로자 170명을 연구대상으로 하였다. 이들에 대해 설문지와 산업의학의사의 면담을 통한 작업관련성 평가를 근거로 정밀대상자를 선정하고 이들에 대해 메타콜린 유발시험, TDI 유발시험 등을 수행하여 직업성천식을 확인하였다. 결과 : 설문조사 결과 11명이 직업과 관련하여 천식증상을 보이는 것으로 나타났고(6.9%), 이중 7명에서 메타콜린 유발검사 양성소견을 보였다. TDI에 의한 특이유발시험 결과 1명에서 양성반응이 나타나, 이 집단에서 TDI에 의한 직업성천식의 유병율은 0.58%였다. 결론 : 과거 국내연구에서 TDI에 의한 직업성천식의 유병율이 2~20%에 이르렀던 데 비해, 본 연구에서는 0.58%로 나타났다. 이는 국외 논문에서도 나타나는 경향으로 작업장 노출량 감소로 점차 발생률이 감소하는 양상을 보이고 있다. 그러나 이미 증상이 나타난 근로자들이 부서를 옮기거나, 직장을 그만둠으로 인해 그 유병율이 과소평가되었을 가능성도 있다고 판단된다. Objecdives: This study was carried out to estimate the prevalence of isocyanate-induced occupational asthma in toluene diisocyanate (TDI) exposed workers. Methods: We examined 170 workers who had been directly exposed to TDI through a medical questionnaire, physical examination, and pulmonary function test. Based on screening examination, workers with suspected occupational asthma were selected for further evaluation such as methacholine and TDI challenge tests. Results: Eleven (6.9%) among 170 workers complained of symptoms of occupational asthma. and 7 among these 11 symptomatic workers showed positive responses to the methacholine challenge test (4.1 %). One spray painter was confirmed as having the TDI induced occupational asthma following a positive response to TDI challenge test. Conclusions: The prevalence of TDI-induced asthma was at 0.58% was lower than that for former studies (2-20%). Improved workplace environment, lower level of TDI exposure compared to the past, and the healthy workers effect may have contributed to this low rate of asthma prevalence in workers with TDI exposure.

새로운 조성을 갖는 고형 탈묵제의 제조

최형철,남기대,정노희 한국공업화학회 2003 공업화학 Vol.14 No.3

펄프섬유로부터 잉크입자를 효율적으로 제거하여 잉크함량이 적고 백색도가 높은 재생펄프용 탈묵제를 제조하였다 본 연구의 또 다른 목적은 고백색도에 필요한 여러 계면활성제의 적정조건을 찾고 재생펄프의 수율을 높이는 것이다. 본 연구에서 우리는 우수한 탈묵효과를 위해 스테아르산과 여러 유형의 계면활성제를 사용하였다. 그리고 탈묵효율에 미치는 여러 가지 고형 탈묵제의 효과를 알기 위하여 부상탈묵실험을 수행하였다. 그 결과 고백색도와 높은 수율을 얻을 수 있는 새로운 고형 탈묵제의 적절한 조합조성은 스테아르산 75%와 폴리옥시알킬렌알킬아릴에테르 6%를 혼합한 것이었다. 또한 탈묵효과를 폭넓게 적용하기 위해 기포력과 피 안정도, 분산능을 테스트하였다. 새로운 타입의 탈묵제는 폐지 탈묵시 우수한 분산능과 적당한 기포력과 안정성을 나타내었다. A new feinting agent for recycling of waste paper was produced. This agent efficiently removed ink particles from the pulp fiber and the resulting recycled pulp had a high brightness and a low content of residual ink. Efforts were made to find an optimum condition of various surfactants used for high brightness and yield of recycled pulp. In this study, stearic acid was used for various types of general surfactants for deinking. Flotation deinking experiments were conducted in order to examine the effect of various solid-type deinking agents. As a restult, an optimum combination of this new solid-type deinking agent, which resulted in high brightness and yield, was 75 wt% stearic acid mixed with 6wt% polyoxyalkylene alkyl aryl ester. This new type deinking agent had good dispersability, suitable foaming power and foam stability in deinking of waste paper.

Rolandic Cortical Dysplasia : 증례보고 Case Report

김형일,정채경,최하영,Palmini, Andre,이민철,이정청 대한신경외과학회 1994 Journal of Korean neurosurgical society Vol.23 No.6

The advent of MRI enables us to make an in-vivo diagnosis of cortical dysplastic lesions which are highly epiletogenic and show the variety of seizure patterns. Authors report a case of rolandic cortical dysplasia who had highly intractable focal motor clonic seizures. Invasive recording with subdural grid was very helpful in delinating the epileptogenic area as well as in functional mapping of eloquent areas. Total removal of dysplastic lesion could treat this highly intractable epilepsy successfully.

공업화부재의 생산/운반/양중관리를 위한 정보가시화 시스템 개발에 관한 연구

임형철,송영석,김창덕,송성진 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1(구조계)

Recently, The construction field in the urban area is short of working space and securing processing place because it is surrounded by adjacent buildings and nearby roads and have difficulties in rising labor costs. The insufficient space causes problems of interference and conflicts in transporting materials and working at the site. Therefore, Construction Manager find many alternative method and select industrialized method. The objective of this paper is to develop and give a method of information visualization system for manufacturing, delivering and lifting these materials in construction project stakeholders, using tools visualizing informations. The tools supports to stakeholders so many informations in material manufacturing, delivering, lifting in construction site. That is, order information, manufacture information in factory, sending information, carrying information, unloading and lifting in Site, and so on. Case studies are performed to evaluate the feasibility and applicability of the proposed method.

칼슘투여가 혈중 지질과 칼슘대사에 미치는 영향

한성철,신말순,전형권 龍仁大學校 1998 용인대학교 논문집 Vol.16 No.-

The study was carried to investigate the effects of a long term calcium upon blood lipid metabolism in athletes, The effects of calcium supplementation and hematological variables which are related to calcium metabolism, Subjects(N=30), who were 30 males of athletes, were randomly assigned to two group(placebo group, N=15, experimental group N= 15. Each subject in experimental group was ingested a tablet containing 500mg of calcium three times a day for 8 weeks. Hematological variable were measured pre and post 2, 4, 6, 8 weeks after the tablets ingestion. The results through the statiscal analysis of blood components, calcium, tatal-cholesterol, HDL-C, LDL-C, Total-cholesterol/HDL-C, in lipid components were as follow; 1) Serum calcium was significantly increased in calcium croup after 2 weeks and maintained through out the entire experimental period(P<0.75), while showed no significant change in placebo group. There were significant differences between two group(calcium croup, placebo group). 2) Total cholesterol was decreased after 2, 4, 6, 8 weeks in Calcium group but there was no significantly decreased in placebo group. 3) LDL-C was significantly decreased in calcium group after 2 weeks and maintained through out the entire experimental period(P<0.05), but there was no significantly decreased in placebo group. There were significant differences between two group(calcium group, placebo group). 4) HDL-C was significantly increased in calcium group after 4 weeks and maintained through out the entire experimental period(P<0.05), while showed no significant change in placebo group. There were significant differences between two group(calcium group, placebo croup). 5) TC/HDL-C was decreased after 2, 4, 6, 8 weeks in calcium group but there was no significantly decreased in placebo croup . There were significant differences between two group (P<0.05).

可變構造시스템(VSS)을 이용한 直流 서어보 驅動裝置 制御에 관한 硏究

李炯基,權世鉉,金錫哲 釜山工業大學校 1990 論文集 Vol.32 No.-

A control system of dc machine position, speed or current control based on variable structure system approach is presented. The deliberate introduction of sliding mode leads to good dynamic and steady state behavior of the overall system. Amethod of the switching function estimation based on control error and armature current information is proposed. In addition the external torque observer is constructed. The simulation of the proposed control result shows that the system motion is as it was predictioned from theoretical analysis.